The advent of the computer has boomed to a point of prolific use in a variety of different areas. Computers are used throughout the world for everything from controlling speed and direction in a vehicle, to making an online order for a new product, to allowing a young child to learn how to count or read. Within the business industry, the use of the computer has greatly increased the efficiency for performing tasks.
The evolution of computing devices, from data crunching devices that occupied entire floors of large office facilities, to laptop computers or other portable computing devices has dramatically impacted the manner in which documents are generated and information is stored. Portable computing capabilities have enabled individuals to type letters, draft memorandum, take notes, create images, and perform numerous tasks in places other than the office using these computing devices. Professionals and nonprofessionals alike are empowered to perform tasks while on the move using devices that fulfill their computing needs in any location.
With the advent of laptop computers and high-capacity personal data assistants, the office workspace has been expanded to include a variety of non-traditional venues in which work is accomplished. To an increasing degree, computer users must become masters of the divergent user interfaces for each of their computing devices. From a mouse and keyboard interface for the standard personal computer to the simplified resistive stylus interface of personal data assistants and even to the minimalistic keys of a cellular telephone, a user is confronted with a variety of different user interfaces that one needs to master before he can use the underlying technology.
Despite the advances in technology, most users tend to use documents printed on paper as their primary editing tool. Some advantages of printed paper include its readability and portability. Others include the ability to share annotated paper documents and the ease at which one can archive printed paper. One user interface that is bridging the gap between advanced computing systems and the functionality of printed paper is a stylus-based user interface. One approach for the stylus-based user interface is to use resistive technology (common in today's PDAs). Another approach is to use active sensors in a laptop computer.
One type of computer system in this area is a handwritten notation system. Handwritten notation systems allow a user to write words and letters in handwritten strokes while a computing system recognizes the strokes to form the intended words. With modern hardware and software, a user can write directly on her computer using an ink input. Many on-line handwriting recognition methods have been proposed in different character sets such as alphabets, digits, Chinese character set, and mathematical character sets. However, there is a real market need for methods and apparatuses that are designed for other types of symbol recognition.